The present invention relates to a wireless power receiver scheme, and more particularly to a multi-mode wireless receiver apparatus and corresponding resonator circuit design.
Generally speaking, for the field of wireless power transfer, a traditional power receiver scheme needs a corresponding number of coils and rectifiers to implement multi-mode wireless power transfer function. For example, the traditional power receiver scheme may need N coils and N rectifiers to implement N mode wireless power transfer function. A conventional wireless power receiver is provided to solve this problem. FIG. 4 is a diagram showing a conventional wireless power receiver 400. The conventional wireless power receiver 400 includes one set of coils (inductors L2, L3, capacitors C2a, C2q, C2b) and one rectifier 405. To implement dual-mode wireless power transfer function, the inductors L2, L3 and capacitor C2q form a resonant loop to generate a frequency response signal while the inductor L3 and capacitor C2a form another resonant loop to generate another frequency response signal. Accordingly, the conventional wireless power receiver 400 can reduce two coils and two rectifiers to one set of coil and rectifier. However, this conventional wireless power receiver inevitably suffers an over voltage rising problem at a light loading condition due to resonant frequency drifts. An over voltage protection may be erroneously triggered at the light loading condition. It is not desirable for the conventional wireless power receiver.